when you're fucking your girl and about to cum, pull out and shoot it in your hand. Make the "spider-man" web slinging hand and fling it on the girls face (or ass, tits, whatever) while making the "pfffft" web slinging sound.

The Urban Dictionary Mug

The webslinger is when your wife or gf won't give you any play, so you retire to the bedroom and sit on the corner of the bed and jerk off. Once she opens the door, you fling the cum directly at her face using the "Spiderman" hand gesture.

"My girl wouldn't give up the stink last night so I waited 20 min in the bedroom just to hit her with the webslinger."